Abstract Background To clarify whether intestinal microbiota and metabolites are associated with the formation of Crohn’s disease(CD)-associated stricturing, and to identify differential bacteria and metabolites. Methods A total of 62 patients with CD B1, 41 patients with B2, and 64 HC were enrolled from the Sixth Affiliated Hospital of Sun Yat-sen University. Fresh fecal samples and relevant clinical data were collected for analysis. The composition of fecal intestinal microbiota were assessed using 16s rDNA sequencing. Metabolome sequencing was employed to investigate the fecal metabolite composition. Results 16s rDNA sequencing revealed a decrease in α diversity in both groups B1 and B2 compared to the group HC, as well as differences in β diversity. However, no significant differences in bacterial diversity were observed between groups B1 and B2. At the phylum level, compared to the group HC, the abundances of Proteobacteria and Fusobacteria were significantly higher in both groups B1 and B2 (P 0.05), while the abundances of Firmicutes、Actinobacteria and Tenericutes were lower (P 0.05). At the genus level, compared to the group HC, the abundances of Roseburia and Veillonella were significantly higher in both groups B1 and B2 (P 0.05), while the abundances of Blautia, Bifidobacterium, Faecalibacterium, Collinsella, Coprococcus, Gemmiger, Prevotella and Clostridium were lower (P 0.05). There were no differences in bacterial composition between the groups B1 and B2. The results of metabolomic sequencing revealed that, compared to the HC group, the levels of metabolites such as Amino Acids, Peptides, Imidazoles, Carnitines and Primary BAs were elevated in both groups B1 and B2 (P 0.05), with a total of 82 metabolites showing increased levels. In contrast, the levels of metabolites such as Short-Chain Fatty Acids (SCFAs), Carbohydrates, Pyridines and Benzoic Acids were decreased (P 0.05), with a total of 49 metabolites showing decreased levels. Eight metabolites, including Arachidonic acid, Glycodeoxycholic Acid (GDCA), Carnitine, Picolinic acid, Indole-3-carboxaldehyde, Indole-3-carboxylic acid, Pipecolic acid and Arginine, exhibited differences between the B1 and B2 groups. Conclusion Compared with the group HC, both groups B1 and B2 patients exhibited significant intestinal microbiota and metabolites disorders, manifesting as decreased bacterial diversity, altered abundances of various bacteria and metabolites. These differential bacteria and metabolites may be involved in the occurrence and development of CD stricturing and intestinal fibrosis. Conflict of interest: Mr. Zhang, Qi: No conflict of interest Zhi, Min: no
Zhang et al. (Thu,) studied this question.